Nadia ate 2 slices of pie. Luis ate 1 slice. If there were initially 5 slices, what fraction of the pie is remaining?
$\text{fraction of pie eaten} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 3 slices, which leaves 2 out of 5 slices remaining. There is $\dfrac{2}{5}$ of the pie remaining.